I have long since realised that different people have different levels of interest in what the hell is actually wrong with me anyway, but unfortunately everyone is forced to ask the question in the same way, because Victorian standards of etiquette insist that adding the phrase "Seriously, though, I don't want some really long explanation" after the phrase "So what is your illness?" is rude. Those crazy Victorians! It's political correctness gone mad.
But I am totally fine with that and equally well aware that, whilst phrases such as "cystic degeneration" and "scooping the tumour out through your nose like in Ancient Egypt" undoubtedly have their place, they may result in queasiness among the populace. Especially when sprung on people unexpectedly.
To this end, I have decided to create a variety of possible explanations for what's wrong with me, and you can select the one that appears most suited to your needs.
The Short Explanation:
There's a gland in your head called the pituitary gland. Mine has a tumour on it.
The Long Explanation:
There's a gland just under your brain called the pituitary gland (see above for a quick explanation) which makes a whole bunch of hormones. My pituitary has developed a tumour known as a pituitary adenoma (see the About section for more details). Fortunately the tumour is benign, but it makes a hormone called Thyroid Stimulating Hormone (TSH), which results in me having too much thyroid hormone; that creates all kinds of exciting symptoms like a superfast heartrate and the shakes.*
The Explanation In German:
Die Hypophyse ist eine endokrine Drüse, die unter dem Hirn liegt. Ich habe einen hypophysären Tumor, der Schilddrüsenhormon macht; also habe ich Symptome von Hyperthyreoidismus.
Leider ist mein Deutsch sehr schlecht, also vielleicht ergibt die vorhergehenden Absätze keinen Sinn...
The Explanation In Rhyme:
The pituitary gland
is like a small grain of sand
(except it's the size of a pea).
It sits in your head,
well-behaved (or, instead,
it might swell up exponentially).
My pituitary gland
is a meanie; he's banned
from attending well-thought-of events.
So now he just chooses
to sulk, and he oozes
hormones, with the worst of intents.
I am happy to create further explanations to suit your explanatory needs, although they may not all be entirely explicatory or, indeed, explicable.
* Incidentally, if I've ever been mean/stupid/lazy/exhibited any other undesirable character traits in your presence, it's probably also because of the tumour. I'm actually a really great person.**
** This may or may not be entirely or indeed at all true >.>